A wide variety of studies have indicated that electrophysiological measures are sensitive to the effects of nicotine and nicotine deprivation. In addition, the predisposition to use tobacco appears to be genetically influenced and is related to differences in various personality dimensions. These findings are reviewed and it is concluded that electrophysiological measures in conjunction with a personality inventory may provide a sensitive metric with which to discriminate individuals prone to use tobacco. The present proposal will employ electroencephalographic (EEG) and event-related potential (ERP) techniques to assess individuals who smoke and who do not smoke. These groups will be selected so that representative individuals who vary from low to medium to high on the sensation-seeking personality scale will be studied, with equal numbers of male and female subjects assessed. The nature of the approach will provide a comprehensive data set on the possible central nervous system differences, as revealed by electrophysiological measures, between smokers and non-smokers with respect to personality variables that are related to the predisposition to use tobacco. The results of the proposed study will determine: (1) whether EEG and ERPs can be used as markers or predictors for increased likelihood for tobacco use in predisposed individuals, (2) whether smokers differ from nonsmokers with respect to specific EEG and ERP measures and personality, and (3) whether males differ from females with respect to these factors.